1. Field of Invention
The invention relates to an insert for the transfer of liquids from vials, for example for the infusion of drugs in a circuit or an infusion line. With regard to the invention a circuit is preferably an extracorporeal circuit and most preferably a hemodialysis circuit. In particular the invention relates to an insert suitable for receiving, engaged thereon, a drug-containing vial.
2. Description of the Prior Art
There are several circumstances in which transfer of a liquid is required from a vial to another circuit. Such circumstances may occur, for example, during therapeutic treatments like intravenous therapy or when a liquid needs to be transferred from a vial to another container. In the following description, specific reference is made to another very important field where liquids need to be transferred from a vial to a circuit, i.e. the field of therapeutic treatments carried out by means of an extra-corporeal circuit, in particular a hemodialysis circuit. Such reference has no limiting intent, since the invention can be effectively used in other fields.
During therapeutic treatment which requires an extra-corporeal circulation it is often required to administer various drugs to the patient. The presence of the extra-corporeal circuit advantageously avoids the need to administer the drug by means of an injection performed directly on the patient.
By way of example haemodialysis treatment is considered below, without the scope of the invention being limited to this specific application.
During haemodialysis it is often required to administer various drugs or therapeutic substances, such as iron, heparin, erythropoietin and vitamins. The infusion of such substances into the extra-corporeal circuit is at present performed by means of conventional syringes. The substance is drawn from the vial in which it is supplied by the manufacturer and is then injected into a special insert provided along the circuit and equipped with a piercible cap. A double transfer of the substance is therefore performed: first from the vial into the syringe and then from the syringe into the circuit.
This operation thus requires the use of disposable materials, such as the syringe in the respective needle, merely in order to transfer the substance from the vial into the circuit. Moreover, the use of needles always involves the risk of the operating staff being pricked.
Moreover, some of the substances mentioned must be administered slowly over a period of a few minutes. It can therefore be easily understood how the administration of various substances to more than one patient represents a considerable amount of work for the nursing staff responsible for the haemodialysis treatment.
Assemblies for the infusion of substances in an extra-corporeal circuit are described for example in detail in the documents EP 0 172 836 and EP 0 713 409. The object of the present invention is therefore to solve at least partially the problems mentioned in connection with the infusion inserts of the known type.